The present invention relates to an electrolyzer, and in particular, to an electrolyzer with electrodes, in which electrolyzing voltage can be reduced by decreasing distance between electrodes.
An electrolyzer comprising an anode and a cathode arranged at opposite positions is widely used in applications such as filter press type electrolyzer.
Filter press type bipolar electrolyzer is used for producing salt, and this is a typical electrolyzing method using the filter press type electrolyzer. In unit electrolyzer used in this filter press type bipolar electrolyzer, thin plates made of materials selected from thin-film forming metal such as titanium, zirconium, tantalum, etc. are molded in pan-like shape and are used as a partition wall on anode side. Partition wall on cathode side is produced from thin plates made of nickel, stainless steel, etc. These partition walls are mounted on an electrolyzer frame. On the partition walls, recesses and projections engaging each other are formed, or two partition walls are connected using a clad material and are integrated.
On anode side and on cathode side of the partition wall, an anode with anode activating coating on it and a cathode with a cathode activating coating containing metal of nickel or platinum family are connected by means such as welding.
Extremely high electric current, i.e. several tens of kA to several hundreds of kA, is normally supplied to the electrolyzer. In this respect, even slight decrease of electrolytic voltage provides surprisingly high effect to reduce the power consumption. Therefore, it is very important to decrease the voltage required for electrolysis.
Among the factors, which exert influence on electrolytic voltage, the decrease of inter-electrode distance is an important factor which contributes to the decrease of electrolytic voltage, and various proposals have been made to decrease inter-electrode distance.